"""Data I/O and storage module for pytcl.

Provides persistent storage backends for pytcl data including:
- HDF5: Efficient storage of large numerical arrays
- SQL: Structured data storage and metadata management

Examples
--------
Store tracking data in HDF5:

>>> from pytcl.io import HDF5Storage
>>> with HDF5Storage() as store:
...     store.open("tracking.h5", mode="w")
...     store.store_array("states", track_states)
...     store.store_scalar("num_tracks", 42)

Query structured data in SQL:

>>> from pytcl.io import SQLStorage
>>> with SQLStorage() as store:
...     store.open("tracking.db", mode="a")
...     store.store_group("mission")
...     store.store_scalar("mission/start_time", 1234567890)
...     keys = store.list_keys("mission")
"""

from pytcl.io.hdf5_storage import HDF5Storage
from pytcl.io.sql_storage import SQLStorage
from pytcl.io.storage import StorageBackend

__all__ = [
    "StorageBackend",
    "HDF5Storage",
    "SQLStorage",
]
